U.S. patent number 9,587,818 [Application Number 14/853,112] was granted by the patent office on 2017-03-07 for led lighting apparatus with improved heat radiation property.
This patent grant is currently assigned to SILICON WORKS CO., LTD.. The grantee listed for this patent is SILICON WORKS CO., LTD.. Invention is credited to Ki Chul An, Eun Ji Jo, Yong Geun Kim, Sang Young Lee, Yun Hee Ra.
United States Patent |
9,587,818 |
Kim , et al. |
March 7, 2017 |
LED lighting apparatus with improved heat radiation property
Abstract
Provided is an LED lighting apparatus with an improved heat
radiation property, which is capable of effectively radiating heat
generated therein. The LED lighting apparatus may include: a light
source unit comprising a plurality of LED groups each having one or
more LEDs; and a driving unit configured to provide a current path
corresponding to light emission of the light source unit. The light
source unit and the driving unit may be arranged on the same
substrate so as to be separated from each other. Among the
plurality of LED groups, the LED group having the largest heat
value may be arranged farthest away from the driving unit, compared
to the other LED groups. Through the above-described arrangement,
the heat radiation property of the LED lighting apparatus can be
improved.
Inventors: |
Kim; Yong Geun (Suwon-si,
KR), Lee; Sang Young (Jeonju-si, KR), An;
Ki Chul (Daegu-si, KR), Jo; Eun Ji (Daejeon-si,
KR), Ra; Yun Hee (Daejeon-si, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
SILICON WORKS CO., LTD. |
Daejeon-si |
N/A |
KR |
|
|
Assignee: |
SILICON WORKS CO., LTD.
(Daejeon-si, KR)
|
Family
ID: |
55406144 |
Appl.
No.: |
14/853,112 |
Filed: |
September 14, 2015 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
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US 20160076753 A1 |
Mar 17, 2016 |
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Foreign Application Priority Data
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Sep 15, 2014 [KR] |
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10-2014-0121777 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05B
45/10 (20200101); H05B 45/44 (20200101); H05B
45/18 (20200101); F21V 29/10 (20150115); H05B
45/56 (20200101); F21Y 2115/10 (20160801) |
Current International
Class: |
H05B
37/00 (20060101); F21V 29/10 (20150101); H05B
33/08 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2014-85918 |
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May 2014 |
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JP |
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2014-157795 |
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Aug 2014 |
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JP |
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10-2011-0019080 |
|
Feb 2011 |
|
KR |
|
10-2011-0125083 |
|
Nov 2011 |
|
KR |
|
10-1308698 |
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Sep 2013 |
|
KR |
|
Primary Examiner: Crawford; Jason M
Assistant Examiner: Bahr; Kurtis R
Attorney, Agent or Firm: Kile Park Reed & Houtteman
PLLC
Claims
What is claimed is:
1. An LED lighting apparatus comprising: a light source unit
comprising a plurality of LED groups each having one or more LEDs;
and a driving unit configured to provide a current path
corresponding to light emission of the light source unit, wherein
the light source unit and the driving unit are arranged on the same
substrate so as to be separated from each other, and among the
plurality of LED groups, the LED group having the largest heat
value is arranged farthest away from the driving unit, compared to
the other LED groups.
2. The LED lighting apparatus of claim 1, wherein the driving unit
is arranged at the center of the substrate, compared to the
plurality of LED groups.
3. The LED lighting apparatus of claim 1, further comprising a
power supply unit configured to provide a rectified voltage using
an AC voltage, wherein the power supply unit is arranged in the
center of the substrate, and the driving unit is arranged adjacent
to the power supply unit.
4. The LED lighting apparatus of claim 1, wherein among the
plurality of LED groups, the LED group having the largest heat
value is arranged at the center of the substrate, compared to the
other LED groups.
5. The LED lighting apparatus of claim 1, wherein a ground voltage
line is formed at the edge of the substrate.
6. The LED lighting apparatus of claim 5, wherein among the
plurality of LED groups, the LED group having the largest heat
value is arranged at the center of the substrate, compared to the
other LED groups, and the driving unit is arranged adjacent to the
ground line.
7. The LED lighting apparatus of claim 1, wherein among the
plurality of LED groups, an LED having a relatively large heat
value is arranged far away from the driving unit, and an LED having
a relatively small heat value is arranged close to the driving
unit.
8. The LED lighting apparatus of claim 7, wherein the plurality of
LED groups sequentially emit light from the LED group arranged
farthest away from the driving unit to the LED group arranged
closest to the driving unit.
9. The LED lighting apparatus of claim 1, wherein the substrate is
divided into a plurality of unit regions each including the light
source unit and the driving unit, and the light source unit and the
driving unit in each of the unit regions are independently
operated.
10. The LED lighting apparatus of claim 1, further comprising a
power supply unit configured to provide a rectified voltage using
an AC voltage, wherein the power supply unit is arranged in the
center of the substrate.
11. The LED lighting apparatus of claim 1, wherein the substrate
includes a plurality of substrates, each of the substrates includes
the light source unit and the driving unit, and in each of the
substrates, the LED group having the largest heat value among the
plurality of LED groups is arranged farthest away from the driving
unit.
12. The LED lighting apparatus of claim 11, wherein the plurality
of substrates include two substrates, and the plurality of unit
regions included in the respective substrates are symmetrically
arranged.
13. The LED lighting apparatus of claim 12, wherein the plurality
of substrates are separated from each other by 1 mm or more.
Description
BACKGROUND
1. Technical Field
The present disclosure relates to an LED lighting apparatus, and
more particularly, to an LED lighting apparatus with an improved
heat radiation property, which is capable of effectively radiating
heat generated therein.
2. Related Art
In order to reduce energy, a lighting apparatus is designed to use
a light source having high light emission efficiency based on a
small amount of energy. Recently, an LED has been used as a
representative light source of the lighting apparatus. The LED is
differentiated from other light sources in terms of various aspects
such as energy consumption, lifetime, and light quality.
Since the LED is driven by a current, a lighting apparatus using
the LED as a light source requires a large number of additional
circuits for current driving.
In order to solve the above-described problem, an AC direct-type
lighting apparatus has been developed to provide an AC voltage to
the LED.
The AC direct-type lighting apparatus is configured to convert an
AC voltage into a rectified voltage, and control the LED to emit
light through a current driving operation using the rectified
voltage. Since the AC direct-type LED lighting apparatus uses a
rectified voltage without using an inductor and capacitor, the AC
direct-type LED lighting apparatus has a satisfactory power factor.
The rectified voltage indicates a voltage obtained by full-wave
rectifying an AC voltage.
The lighting apparatus may include a light source unit, a power
supply unit, and a driving unit. The light source unit may include
a plurality of LED groups, the power supply unit may provide a
rectified voltage using an AC voltage, and the driving unit may
drive the light source unit.
Among the units of the lighting apparatus, the LED groups of the
light source unit generate heat at a considerably high temperature,
when emitting light, and the driving unit also generates heat at a
high temperature due to a driving current corresponding to the
light emission.
When the heat of the LED groups or the driving unit is not
effectively discharged, a line pattern may float due to a
difference in thermal expansion coefficient between the line
pattern and a printed circuit board (PCB) or the lifetime of the
LEDs included in the LED groups may be reduced by accumulated
thermal fatigue.
The driving unit is arranged on the PCB without considering the
influence of heat radiated from the LED groups. Thus, the driving
unit may be positioned in the environment which is not suitable for
heat radiation. When the heat radiation is not smoothly performed
due to such an environment, the driving performance and reliability
of the driving unit may be reduced.
For such reasons, the light emission property and brightness of the
LEDs may be degraded, and the entire driving performance and
reliability of the lighting apparatus may be degraded.
Thus, the lighting apparatus needs to be designed to have an
improved heat radiation property.
SUMMARY
Various embodiments are directed to an LED lighting apparatus
capable of improving the heat radiation property thereof by
improving the arrangement of LED groups and a driving unit,
improving the light emission characteristic and brightness of LEDs,
and improving the driving performance and reliability thereof.
Also, various embodiments are directed to an LED lighting apparatus
in which the LED group having the largest heat value among a
plurality of LED groups is arranged farthest away from the other
LED groups, thereby improving the driving environment of a driving
unit.
Also, various embodiments are directed to an LED lighting apparatus
which determines the positions at which a plurality of LED groups
are arranged, in consideration of heat values, thereby improving
the heat radiation property thereof.
In an embodiment, an LED lighting apparatus may include: a light
source unit comprising a plurality of LED groups each having one or
more LEDs; and a driving unit configured to provide a current path
corresponding to light emission of the light source unit. The light
source unit and the driving unit may be arranged on the same
substrate so as to be separated from each other. Among the
plurality of LED groups, the LED group having the largest heat
value may be arranged farthest away from the driving unit, compared
to the other LED groups.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram schematically illustrating an LED lighting
apparatus with an improved heat radiation property in accordance
with an embodiment of the present invention.
FIG. 2 is a diagram illustrating the arrangement structure of a
substrate forming the LED lighting apparatus in accordance with the
embodiment of the present invention.
FIG. 3 is a diagram illustrating the arrangement structure of an
LED lighting apparatus in accordance with another embodiment of the
present invention.
FIG. 4 is a diagram illustrating the arrangement structure of an
LED lighting apparatus in accordance with another embodiment of the
present invention.
DETAILED DESCRIPTION
Hereafter, exemplary embodiments of the present invention will be
described in detail with reference to the accompanying drawings.
The terms used in the present specification and claims are not
limited to typical dictionary definitions, but must be interpreted
into meanings and concepts which coincide with the technical idea
of the present invention.
Embodiments described in the present specification and
configurations illustrated in the drawings are preferred
embodiments of the present invention, and do not represent the
entire technical idea of the present invention. Thus, various
equivalents and modifications capable of replacing the embodiments
and configurations may be provided at the point of time that the
present application is filed.
FIG. 1 is a diagram schematically illustrating an LED lighting
apparatus with an improved heat radiation property in accordance
with an embodiment of the present invention.
The LED lighting apparatus with an improved heat radiation property
in accordance with the embodiment of the present invention may
include a power supply unit 10, a light source unit 20, and a
driving unit 30. The light source unit 20 may include a plurality
of LED groups.
The power supply unit 10 may output a rectified voltage Vrec
obtained by converting an AC voltage, and include an AC voltage
source VAC and a rectifier circuit 12. The AC voltage source VAC
may supply the AC voltage, and the rectifier circuit 12 may rectify
the AC voltage and output the rectified voltage Vrec. The AC
voltage source VAC may include a commercial AC voltage source.
The rectifier circuit 12 may full-wave rectify a sine-wave AC
voltage of the AC voltage source VAC, and output the rectified
voltage Vrec. Thus, the rectified voltage Vrec may have a ripple in
which the voltage level thereof rises/falls on a basis of the half
cycle of the commercial AC voltage.
The light source unit 20 may include a plurality of LED groups
connected in series. In the embodiment of the present invention, an
LED lighting apparatus including four LED groups will be taken as
an example for description. However, the number of LED groups will
be freely adjusted according to the capacity of the lighting
apparatus.
Each of the LED groups LED1 to LED4 may include one or more LEDs
connected in series or parallel. In the embodiment of the present
invention, suppose that each of the LED groups LED1 to LED4
includes a plurality of LEDs connected in series. In FIG. 1, only
the first and last LEDs among the plurality of LEDs connected in
series are illustrated, and the connection relation of the LEDs in
the middle is omitted and illustrated as a doted line.
The LED groups LED1 to LED4 of the light source unit 20 may be
sequentially turned on or off in response to changes of the
rectified voltage Vrec.
The driving unit 30 may provide a current path in response to light
emission of the LED groups LED1 to LED4. At this time, the driving
unit 30 may provide different current paths to the respective LED
groups LED1 to LED4.
The driving unit 30 may sense a driving current flowing through the
current paths, and regulate the driving current on the current
paths for sequentially turning on/off the LED groups LED1 to
LED4.
FIG. 2 is a diagram illustrating the arrangement structure of a
substrate forming the LED lighting apparatus with an improved heat
radiation property in accordance with the embodiment of the present
invention.
Referring to FIG. 2, the LED lighting apparatus in accordance with
the embodiment of the present invention may include the power
supply unit 10, the light source unit 20, and the driving unit 30,
which are arranged on the same surface of the substrate 100. The
power supply unit 10 and the driving unit 30 may be implemented as
a chip and mounted on the substrate 100.
The substrate 100 may be formed in a circuit shape. The power
supply unit 10 may be arranged in the center of the substrate 100.
The light source unit 20 may be arranged on the substrate 100
around the power supply unit 10, and the driving unit 30 may be
arranged at the edge of the substrate 100. The substrate 100 may
include a line pattern formed thereon, and the power supply unit
10, the light source unit 20, and the driving unit 30 may be
electrically connected through the line pattern. The line pattern
may include a line for applying the rectified voltage Vrec from the
power supply unit 10 to the light source unit 20, lines for
connecting the LED groups LED1 to LED4 of the light source unit 20
to terminals of the driving unit 30, respectively, a ground voltage
line GND for grounding, and a line connected to the ground voltage
line GND to ground the driving unit 30.
The power supply unit 10 may be arranged in the center of the
substrate 100, and supply the rectified voltage Vrec obtained by
rectifying the AC voltage to the light source unit 20 and the
driving unit 30 through the lines formed on the substrate 100.
In the embodiment of the present invention, the power supply unit
10 for supplying the rectified voltage Vrec may be arranged in the
center of the substrate 100, and the ground voltage line GND may be
formed at the edge of the substrate 100.
When the ground voltage line GND is formed at the edge of the
substrate, the pattern of the lines for the LED groups may be
easily implemented. At a region where power is unstable, a large
amount of leakage current may occur. However, when the ground
voltage line GND is formed at the edge of the substrate 100, the
ground voltage line GND may protect the internal device from noise
such as leakage current. Thus, the lighting apparatus may be stably
operated.
The light source unit 20 may include a plurality of LED groups each
including a plurality of LEDs.
Among the plurality of LED groups, the LED group LED1 having the
largest heat value in response to light emission may be arranged at
the center of the substrate 100, compared to the other LED groups.
Furthermore, the LED group radiating the smallest heat value may be
arranged at the edge of the substrate 100.
When the LED group LED1 having the largest heat value is arranged
close to the center of the substrate, the LED group LED1 may be
arranged farthest away from the driving unit 30 positioned at the
edge. Then, the influence of heat generated from the LED group LED1
on the driving unit 30 implemented as an integrated circuit chip
can be minimized.
The driving unit 30 may be arranged farthest away from the center
of the substrate 100 or at the edge of the substrate 100. When the
driving unit 30 is arranged at the edge of the substrate 100, the
heat generated from the driving unit 30 may be more easily
discharged to the outside of the substrate 100 than when the
driving unit 30 is arranged close to the center of the substrate
100.
When the temperature of an integrated circuit chip rises, a problem
may occur in the reliability of operation thereof. In the
embodiment of the present invention, as the driving unit 30 is
arranged at the edge of the substrate 100, the driving unit 30 may
be arranged farthest away from the LED group LED1 having the
largest heat value. Thus, the driving unit 30 can effectively
discharge heat generated therefrom to the outside, without being
influenced by the heat generated from the LED group LED1 having the
largest heat value. Thus, the driving unit 30 can be driven in a
stable temperature environment in which thermal fatigue is not
accumulated.
Only the driving unit 30 and the light source unit 20 may be
arranged on the substrate 100, and the power supply unit 10 may be
arranged on another substrate.
The light source unit and the driving unit may be mounted on each
of a plurality of unit regions 101 to 105 included in one
substrate.
When a large-capacity lighting apparatus includes one light source
unit and one driving unit on one substrate and a trouble occurs in
one or more of the light source unit and the driving unit, the
entire functions of the lighting apparatus may not be normally
performed or some functions such as brightness control may not be
controlled.
In order to solve the problem, the embodiment of the present
invention discloses the structure in which the substrate 100 is
divided into the plurality of unit regions 101 to 105. The light
source unit and the driving unit may be arranged in each of the
unit regions 101 to 105, and independently operated. Thus, although
a problem occurs in the unit region 101, the light source units and
the driving units in the other unit regions 102 to 105 may be
normally operated. Thus, it is possible to prevent the
above-described problem that the entire functions of the lighting
apparatus are not normally performed or some functions such as
brightness control are not controlled.
In FIG. 2, the unit regions 102 to 105 may be configured in the
same manner as the unit region 101. Thus, illustration of the LED
groups LED1 to LED4 in the unit regions 102 to 105 is omitted.
FIG. 3 is a diagram illustrating the arrangement structure of an
LED lighting apparatus with an improved heat radiation property in
accordance with another embodiment of the present invention.
Referring to FIG. 3, the LED lighting apparatus in accordance with
the embodiment of the present invention may include a power supply
unit 10 arranged at the center of a substrate 100 formed therein, a
driving unit arranged around the power supply unit 10, and a light
source unit 20 arranged at the edge of the substrate 100.
The LED lighting apparatus of FIG. 3 is different from the LED
lighting apparatus illustrated in FIG. 2 in that the driving unit
30 is arranged at the center of the substrate 100 and the light
source unit 20 is arranged at the edge of the substrate 100.
In the case of a general LED lighting apparatus, the driving unit
generates a larger amount of heat than the light source unit. In
this case, as illustrated in FIG. 2, the light source unit and the
driving unit may be arranged to be separated from each other, and
the driving unit may be arranged at the edge of the substrate.
However, in the case of an LED lighting apparatus in which the
light source unit generates a larger amount of heat than the
driving unit, the driving unit may be arranged close to the center
of the substrate 100, and the light source unit having a large heat
value may be arranged at the edge of the substrate 100, as
illustrated in FIG. 3. In this case, the heat of the substrate 100
can be more effectively discharged.
At this time, the LED group LED1 having the largest heat value may
be arranged at the edge of the substrate 100, and the LED group
having the smallest heat value may be arranged close to the center
of the substrate 100.
That is, as the LED group LED1 having the largest heat value is
arranged at the edge of the substrate 100, the heat generated from
the light source unit 20 can be easily discharged to the outside of
the substrate 100. Furthermore, the LED group LED1 having the
largest heat value may be arranged farthest away from the driving
unit 30, thereby minimizing the influence of heat generated from
the LED group LED1 on the integrated circuit chip of the driving
unit 30.
FIG. 4 is a diagram illustrating the arrangement structure of an
LED lighting apparatus with an improved heat radiation property in
accordance with another embodiment of the present invention.
In the embodiments of FIGS. 2 and 3, the power supply unit, the
light source unit, and the driving unit may be arranged on one
substrate 100. In the embodiment of FIG. 4, however, the power
supply unit, the light source unit, and the driving unit may be
arranged on each of two substrates 110 and 120, and independently
operated.
When the power supply unit 10, the light source unit 20, and the
driving unit 30 are arranged on each of the two substrates 110 and
120 as illustrated in FIG. 4, one substrate 120 may be
independently operated even though another substrate 110 is not
operated due to a problem. That is, the lighting apparatus can
perform a lighting operation through light emission of the LED
groups mounted on the substrate 120. Thus, the entire lighting
operation of the LED lighting apparatus can be performed without a
problem.
The plurality of substrates 110 and 120 may be divided into a
plurality of unit regions 111 to 113 and a plurality of unit
regions 121 to 123, respectively, and the light source unit 20 and
the driving unit 30 may be arranged in each of the unit
regions.
As the plurality of substrates are separated from each other by 1
mm or more, the influence between the respective substrates may be
minimized. That is, a margin in which the substrates can be
extended by heat generation can be secured, and heat exchange
therebetween can be reduced.
Furthermore, the light source units 20 and the driving units 30
arranged in the respective unit regions 111 to 113 of the substrate
110 and the light source units 20 and the driving units 30 arranged
in the respective unit regions 121 to 123 of the substrate 120 may
be symmetrically arranged.
FIG. 4 illustrates two substrates. Depending on embodiments,
however, the power supply unit, the light source unit, and the
driving unit may be arranged on each of three or more
substrates.
FIG. 4 illustrates that the light source unit 20 is arranged close
to the center of the substrate and the driving unit 30 is arranged
at the edge of the substrate. However, the driving unit 30 may be
arranged close to the center of the substrate and the light source
unit 20 may be arranged at the edge of the substrate.
In the embodiment of the present invention, an AC direct type
lighting apparatus has been taken as an example for description.
However, the LED lighting apparatus in accordance with the
embodiment of the present invention can be applied to a general LED
lighting apparatus as well as the AC direct type lighting
apparatus.
In the embodiments of the present invention, the light source unit
and the driving unit to drive the LED groups may be arranged to be
separated from each other. Thus, as the heat generated from the
driving unit and the light source unit is effectively discharged,
the damage of the LED groups and the driving units can be
prevented, and the lifetime of the LED lighting apparatus can be
increased. Therefore, the entire performance of the LED lighting
apparatus can be improved.
Furthermore, the driving unit and the light source unit are
arranged to be separated from each other, and the LED group having
the largest heat value among the plurality of LED groups may be
arranged farthest away from the driving unit, thereby minimizing
the influence of heat generated from the LED group on the driving
unit.
In accordance with the embodiment of the present invention, the
arrangement of the driving unit and the LED groups of the light
emission unit may be determined in consideration of the heat
radiation property. Thus, the heat radiation property of the LED
lighting apparatus can be improved, the light emission property and
brightness of the LEDs can be improved, and the driving performance
and reliability of the LED lighting apparatus can be improved.
Furthermore, among the plurality of LED groups, the LED group
having the largest heat value may be arranged farthest away from
the driving unit, compared to the other LED groups. Thus, as the
driving environment of the driving unit which is relatively
vulnerable to heat is improved, the driving performance and
reliability can be improved.
Furthermore, the positions at which the plurality of LED groups are
arranged may be determined in consideration of heat values. Thus,
the heat radiation property of the LED lighting apparatus can be
improved.
While various embodiments have been described above, it will be
understood to those skilled in the art that the embodiments
described are by way of example only. Accordingly, the disclosure
described herein should not be limited based on the described
embodiments.
* * * * *